Typically, mechanically bound books are created using either relatively small, inexpensive machines that require a significant amount of labor to create each book, or large, expensive machines that require much less labor per book. Use of small, inexpensive machines is widespread inasmuch as they are present in many offices. Such machines are adequate for creating relatively small quantities of books, provided the operator has received some training in their use and has sufficient time to devote to the effort of making the books. As the number of books to be assembled increases, however, the manpower required is significant when utilizing such small, inexpensive machines. In practice, it is not uncommon for operators to spend an hour or more assembling twenty to fifty books.
Automated machines, on the other hand, are relatively uncommon in offices. Rather, they are most often found in dedicated print shops or binderies. While these machines may be capable of creating the twenty to fifty books in as little as two to five minutes, the size and cost of automated machines can be prohibitive to smaller or occasional users. As a result, these more efficient, automated machines are typically available to only a very small percentage of people who desire mechanically bound books. Further, it is often time consuming for operators to set up such automated machines or to modify machines to change from one size or color of binding element to another. The specialized training required to operate and set-up automated binding machines further limits benefits available to general office users.
The preceding two decades have witnessed a dramatic change in the way documents are created and printed, however. The advent and adoption of personal computers and word processing software have greatly increased the user's options for production of documentation. Significant decreases in the cost of computers and printers, along with significant strides in efficiency and power have allowed nearly anyone the ability to design and print pamphlets, manuals, books, calendars and the like. As the ability to design and print documents has become widespread, the amount of time required to create a document has dropped dramatically. Unfortunately, however, for a majority of the people creating these documents, the ability to do mechanical binding has not improved significantly over the past two decades.
The ability to mechanically bind documents has not kept pace with the ability to create, edit and print the documents due in large part to fundamental problems with the currently available binding styles. Various types of binding elements have been utilized to mechanically bind a stack of perforated sheets or the like, including metal spiral wire or plastic spiral, double loop wire, wire comb, or hanger-type designs, plastic comb, hot-knife or cold-knife strip (marketed by the assignee of the present invention as VeloBind®), loose leaf binders, such as 3-ring binders, and other dedicated mechanical binding structures, such as the assignee's ProClick®. Examples of such binding elements which are of a wire comb or hanger-type design are disclosed, for example, in U.S. Pat. No. 2,112,389 to Trussell and U.S. Pat. Nos. 4,832,370 and 4,873,858 to Jones, while machines for assembling such binders are disclosed in U.S. Pat. No. 4,031,585 to Adams, U.S. Pat. No. 4,398,856 to Archer et al., U.S. Pat. No. 4,525,117 to Jones, U.S. Pat. No. 4,934,890 to Flatt, and U.S. Pat. No. 5,370,489 to Bagroky. Other binding devices are disclosed, for example, in the following references: U.S. Pat. Nos. 2,089,881 and 2,363,848 to Emmer, U.S. Pat. No. 2,435,848 to Schade, U.S. Pat. No. 2,466,451 to Liebman, U.S. Pat. No. 4,607,970 to Heusenkveld, U.S. Pat. No. 4,904,103 to Im, U.S. Pat. No. 5,028,159 to Ammich et al., U.S. Pat. No. 4,369,013, Reexamination Certificate B1 U.S. Pat. Nos. 4,369,013 and Re. 28,202 to Abildgaard et al. Machines for assembling plastic comb or finger binding elements are disclosed in patents such as U.S. Pat. No. 4,645,399 to Scharer, U.S. Pat. No. 4,900,211 to Vercillo, U.S. Pat. No. 5,090,859 to Nanos et al., and U.S. Pat. No. 5,464,312 to Hotkowski et al. Nail-type and VeloBind® elements are disclosed in patents such as U.S. Pat. No. 4,620,724 to Abildgaard et al., and U.S. Pat. Nos. 4,685,700, 4,674,906, and 4,722,626 to Abildgaard. All patents and publications referenced in this disclosure are included herein by reference.
Non-spiral binding elements typically include a spine from which a plurality of fingers extends that may be assembled through perforations in a stack of sheets. This spine may be linear, with or without a longitudinally extending hinge. Alternately, the spine may be formed by sequential bending of a wire, as with wire comb or hanger type binding elements. While each of these binding arrangements has its advantages, each suffers from various limitations particular to the type of binding.
Due to the structure of such binding devices, which typically include elongated spines and fingers, the binding devices commonly become entangled when stored in a group. Detangling the binding elements in order to assemble and individual element into a stack of sheets or lay the element into a binding machine can be a tedious and potentially time-consuming process. Further, this tendency to become entangled may complicate or prevent the use of such binding devices in automated binding processes or machines wherein an automated feed is desirable. The time required to manually feed binding elements into a machine would be prohibitive to efficient, high-volume automated binding operations. Moreover, maintaining an inventory of such binding elements in an automated machine can require a large volume of space within the machine, necessitating a relatively large footprint.
Due to the structure of such binding devices, which typically include predetermined length of fingers for a given binding element, the binding devices are commonly utilized to bind pre-selected thicknesses of stacks of sheets or, alternately, only a limited range of thicknesses of stacks of sheets. As a result, a user that may have the occasion to bind a larger range of stack thicknesses would be required to maintain an inventory of a range of sizes of binding elements. This inventory of various sizes of binding elements may be further multiplied when a user may bind a range of sizes of sheets themselves, i.e., when the stacks of sheets to be bound vary in length. This problem would be compounded in an automated binding process, requiring a large element storage space within the machine and/or frequent element changes within the machine to accommodate varied book sizes.
In order to accommodate varying thicknesses of stacks of sheets to be bound, various binding designs have been proposed. U.S. Pat. No. 2,779,987 to Jordan discloses a first strip from which two prongs extend, each of which is received in an opening in a retaining strip, wherein the retaining strip includes a ratcheting structure that secures the prong in position. More commonly used designs typically include a pair of bendable prongs extending from a first strip, which are inserted through openings in the stack of sheets and then into openings in a retaining strip. Each bendable prong is then bent over such that it is disposed substantially adjacent the axis of the retaining strip and then held in position by an interlocking structure or a locking flange or the like, which is slid over the bent end of the prong. Examples of binding structures of this type are disclosed in patents such as the following: U.S. Pat. No. 699,290 to Daniel; U.S. Pat. No. 2,328,416 to Blizard et al.; U.S. Pat. No. 3,224,450 to Whittemore et al.; U.S. Pat. No. 4,070,736 to Land; U.S. Pat. No. 4,121,892 to Nes; U.S. Pat. No. 4,202,645 to Sjöstedt; U.S. Pat. No. 4,288,170 to Barber; U.S. Pat. No. 4,302,123 to Dengler et al.; U.S. Pat. Nos. 4,304,499, 4,453,850, and 4,453,851 to Purcocks; U.S. Pat. No. 4,305,675 to Jacinto; and Great Britain Patent 1,225,120. In such designs, the user can typically reopen the resulting bound structure in order to remove or add further sheets.
A more complex design is disclosed in U.S. Pat. No. 3,970,331 to Giulie. The Giulie design is intended for use in libraries or other institutions for replacing the bindings on books or providing permanent bindings on magazines or the like. The binding structure is designed for assembly without the use of expensive machinery for clamping a book together, or the application of heat or mechanical pressure. The Giulie binding structure includes a pair of backing strips that are positioned along opposite sides of the stack of sheets adjacent preformed holes along one edge of the stack. One of the backing strips includes a plurality of studs having ratchet teeth, the other including a series of holes having a mating ratchet tooth. The studs ratchet through the holes, and a blocking means on the receiving strip is generally broken off of the strip and forced into the opening to permanently couple the studs within the openings. The studs may then be broken off or cut off. Thus, a book formed in this manner cannot be opened to edit the contents and then reengaged. Moreover, such a bound book cannot be readily folded back on itself, or lie open in a surface.
Such binding elements are not generally adaptable to highly automated binding machines. Automated binding machines require a supply of binding elements be located in or proximal to the device. The greater number of binding elements that can be loaded into a binding element magazine, the longer the machine can run without operator intervention. A smaller the overall size of the magazine, however, theoretically allows the machine to be designed with a smaller physical size.
While an element magazine of fifty to one hundred binding elements would seem ideal for general office use, the bulky nature of most currently available binding elements would generally make magazines required to accommodate such a large number of binding elements impractical. Loose-leaf binders, for example, are the poor from this standpoint inasmuch as the integral covers and ring assemblies take up considerable space. Although they can be nested one inside the other, a magazine of considerable length would be required to accommodate fifty to one hundred loose-leaf binders. Even if alternatingly stacked, this requires a considerable volume. For example, fifty binders capable of binding a one-half inch thick document would have a volume of 1700 cubic inches. Similarly, fifty plastic comb, metal spiral, double ring wire or plastic spiral binding elements would each require a volume on the order of 240 cubic inches, respectively, assuming that they are not allowed to mesh within each other and that they are provided to the machine already formed. ProClick® binding elements of the assignee of the present invention, assuming each element is provided to the machine in its open state, would require on the order of 320 cubic inches, while VeloBind®, likewise binding elements of the present assignee, would require on the order of 206 cubic inches. Each of these approximate volumes assumes that the elements are able rest in contact with each other in their most compact organization. Accordingly, these volume estimates do not include any provision for controlling orientation or assisting in delivery to the machine.
Packaging binding elements for automation presents significant additional challenges. The durability of the binding element itself may limit the methods by which binding elements are provided to an automated machine. Metal spiral and double loop wire, for example, are constructed of a thin metallic wire, which is relatively easy to deform, either before binding, which will make binding difficult or impossible, or after binding, which may impair page turning or damage the sheets themselves. Inasmuch as metal spiral and double loop wire binding elements are particularly susceptible to damage prior to binding, packaging of the binding element must protect the element for delivery to the binding machine.
Alternately, metal spiral and plastic coil elements are more efficient spatially when only the filament is provided to the binding machine and the binding machine itself creates the spiral or coil shape and binds the book. This method is utilized by many binderies in large, automated machines today. For fifty or one hundred elements, however, the space savings of this packaging are more than offset by the space required by the forming mechanism itself. Further, such coil formers introduce additional costs, as well as reliability and operator training issues.
When previously formed binding elements are utilized, not only must the element magazine contain a sufficient quantity of binding elements to minimize operator loading, it must support, align and present the binding elements in a form suitable for interaction with the binding machine. Thus, the binding elements must be presented such that the binding machine may remove an element from the magazine and position it in the binding mechanism for interaction with a stack of sheets and before finally finishing the book. The structure of virtually all loose binding elements, i.e. the elongated spine and fingers, makes them highly prone to tangling unless the elements are controlled by the magazine. Even plastic combs, which individually appear generally as a hollow tube with radial slots, sometimes become entangled when the spine of one element slips under the wrapped edge of another. As a result, if the packaging method does not control the elements, the binding machine must have sufficient mechanism to disentangle the elements. Such detangling mechanisms would presumably be prohibitively complex, as well as expensive and unreliable.
Large automated machines have attempted to control binding elements to eliminate or minimize tangling in various ways. For example, double loop wire is often formed as a continuous “rope” that is wound around a spool. To prevent entangling on the spool, a strip of paper or other separator material is wound jointly with the element to act as a barrier. This paper strip must be then unwound as the element is used and disposed of by the binding machine. Beyond the fact that the spools tend to be quite large (15-inch diameter spool that is 15 inches wide has a volume of 2650 cubic inches), this method adds cost to the element packaging, creates a waste product and adds an extra step during element changeover.
Plastic comb has been automated by attaching the binding elements to a continuous web of fanfold paper using an adhesive, as shown, for example, in U.S. Pat. No. 5,584,633. The machine drives the paper using a tractor feed system and separates individual elements from the paper as needed. In practice, this system can be problematic, however, inasmuch as the adhesive may be sensitive to time and environmental factors. If the adhesive does not adequately retain the elements, the elements will either disconnect from the paper completely, or twist or rotate on the paper, resulting in waste elements and/or causing jams within the binding machine.
Plastic coil elements have also been delivered to binding machines in compartmented cartridges that keep each element separated from the others, preventing entangling, as shown, for example, in U.S. Pat. No. 5,669,747. This system typically has the obvious disadvantages of high packaging cost and generally poor packing efficiency. The exception to this general rule has been VeloBind®, which is a two-part binding element structure with plastic male nails from one strip being received in female openings of another strip. VeloBind® has been efficiently packaged in cassettes of one hundred strips (e.g., U.S. Pat. Nos. 4,844,974, 5,051,050, and 5,383,756). While VeloBind® has proven to be a successful packaging and automation solution, a document bound with VeloBind® type elements cannot “lay flat”, i.e., remain opened flat without the user holding the pages. This characteristic limits VeloBind's® potential with users seeking a pure “lay flat” bound book arrangement. Further, the VeloBind® element does not allow pages to cleanly “wrap around” behind the book after turning, a feature that allows the document to consume less space during use.
Dimensional stability of the binding elements themselves also significantly affects automated binding processes. Many mechanical binding styles have inherent manufacturing variations or material properties that make it difficult to automate them successfully. For example, double loop wire consists of a single wire filament formed into a comb pattern. The fingers of the comb are then bent toward the spine to create a “C” profile. The binding process then forces the fingers toward their opposing root on the spine, closing the element and creating a round “O” shape. Since the metallic wire has some inherent elastic properties, the tips of the fingers must be forced past the root some distance in order to ensure the element is closed after spring back. The amount of over-travel necessary to get a correct bind depends on the diameter of the wire, the diameter of the loop, the wire material properties and any work hardening induced on the metallic wire during forming of the “C” shape. Manufacturers of wire binding elements use different brands of wire filament and utilize slightly different profiles for the shape of the loops. Within a given manufacturer's double loop wire binding elements, standard manufacturing tolerances will also cause enough variation from box to box that the required over-travel is not necessarily consistent. These variations require a binding machine to have an adjustable closing stroke or stop position, not only for size changes, but also for each batch of wire elements. This may be acceptable if the machine is being set up for a long run or an operator is in constant attendance. Unfortunately, however, it is very difficult to create an easy to set up, easy to change, reliable binding machine in view of such variations.
Pitch is also a concern with regard to automation of binding processes to provide a bound book with a professional appearance. Pitch is a particular problem with double wire in that the spacing between successive finger loops is not necessarily constant. As the comb shape is formed from a single filament, there is no continuous feature, or spine, on the element that holds each finger in position relative to the next one. The binding machine must then constrain or guide the fingers in order to ensure that they properly line up with the perforations in the sheets to be bound. This is also a problem for metal spiral and plastic coil binding elements. As these elements are, in essence, springs with a low spring constant, the binding machine must control and guide the axial position of the leading point on the element as it is rotated through the document.
Plastic coils have an additional disadvantage caused by their material properties. A plastic coil element is generally an extruded vinyl filament that is heated to a softening temperature range and wound around a mandrel before being allowed to cool. This process tends to leave stresses in the binding element similar to that found in injection molded plastic pieces. If the element is subsequently exposed to elevated temperatures, these stresses will cause the element to “relax,” changing the diameter, and, thus, the length of the element. Due to the low melt temperature of vinyl, these elevated temperatures can potentially be encountered during normal transportation, storage and usage. This is particularly problematic in the summer when the elements may be in a truck for several days during the transportation stage. These dimensional changes make feeding the element through the perforations more difficult and can impair the crimping process used to prevent the element from rotating out of the sheets after binding.
Thus, each of the binding elements currently known and available in the industry presents certain disadvantages, either in the packaging of the elements prior to binding, the automation of the binding process in connection with the elements, or in the qualities of a book bound by the elements. Even traditional loose-leaf binders are bulky and not readily, compactly packaged. They are cumbersome during use, and take up considerably more space than the documents they enclose. Further, even if the cover of a loose-leaf binder can wrap around behind the binder, the individual pages certainly cannot.